Electrical switch device with detachable switch blade carriers and a wiping common contact element



Sept. 9 J. R. HERRERA ETAL 3,

ELECTRICAL SWITCH DEVICE WITH DETACHABLE SWITCH BLADE CARRIERS AND AWIPING COMMON CONTACT ELEMENT Filed Nov. 1, 1961 2 Sheets-Sheet 1 FIG IFIG 50 I INVENTORS. JOE R. HERRERA RICHARD E GlLDART fl PJ-7g4/ $15M ATTORNE YS Sept. 21, 1965 J. R. HERRERA ETAL 3,207,370

ELECTRICAL SWITCH DEVICE WITH DETACHABLE SWITCH BLADE CARRIERS AND AWIPING COMMON CONTACT ELEMENT Filed Nov. 1, 1961 2 Sheets-Sheet 2 FIG245 H6 7 INVENTORS.

JOE R. HERRERA BY RICHARD F GILDART A TTORNEYS.

United States Patent ,2 9 ELECTRICAL SWITCH DEVICE WITH DETACH- ABLESWITCH BLADE CARRIERS AND A WIPING COMMON CONTACT ELEMENT Joe R.Herrera, Downey, and Richard F. Gild'art, Montebello, Calif., assignorsto Rehrig Pacific Company, Los Angeles, Calif., a corporation ofCalifornia Filed Nov. 1, 1961, Ser. No. 149,346 Claims. (Cl. 200'-61.41)

The present invention relates in general to electrical switches and moreparticularly to electrical switches which are actuated by an article orobject moving along a path.

An object of this invention is to provide an electrical switch having acommon contact element for a plurality of individual contact elements inwhich the number of individual contact elements may be increased ordecreased to suit any requirement.

Another object of this invention is to provide an electrical switchhaving a common contact element for a plurality of individual contactelements in which the individual contact elments are easily replaceableor removable.

Another object of this invention is to provide an electrical switchhaving a common contact for a plurality of individual contact elementsin which all of the individual contact elements make a wiping contactwith the common contact element.

Still another object of this invention is to provide a switch having acommon contact for a plurality of individual contact elements in whichthe individual contact elements need not be in exact alignment with thecommon element for satisfactory'operation.

The invention features a switch frame, a common contact elementinsulatingly mounted on the frame comprising a helical spring which isnormally under tension, and one or more fingers or projections on theframe. One

or more carriers, detachably fitted over the fingers or projections andheld in place by cooperating detent elements, pivotally carry a switchblade, the thickness of the switch blade being less than the spacingbetween successive convolutions of the helical spring contact element.

These and other objects, advantages and features of this invention willbecome more apparent by reference to the accompanying drawings and thefollowing detailed description in which a specific embodiment of theinvention is set forth by way of illustration.

In the drawings:

FIG. 1 is an isometric view of a switch embodyingthe invention;

FIG. 2 is a partially exploded view of a switch embodying thisinvention;

FIG. 3 is a rear elevatiorial view of the switch frame showing severalswitch blade assemblies as they are mounted on the frame;

FIG. 4 is a partial isometric view of the switch showing the actuationof one of the switch elements by an object moving along apath;

FIG. 5 is an isometric view of one of the switch blade elements and itscarrier detached from the switch frame;

FIG. 5a shows a modified form of a spring strip;

FIG. 6 is a cross-sectional view taken on line 66 of FIG. 3;

FIG. 7 is a cross-sectional view taken on line 77 of FIG. 3 and showsone of the switch elements actuated;

FIG. 8 is a cross-sectional view taken on line 8-8 of FIG. 5; and

FIG. 9 is a cross-sectional view of the cooperating detent elements onthe frame and carrier.

As shown in FIGS. 1 and 2 the switch comprises a rectangular casing orhousing 10 having a back wall 11,

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and a switch frame 17 secured in the housing 10 by screws passingthrough flanges 18 and 19. Body portion 20 of the frame 17 forms apartial front wall for the housing 10.

The body portion 20 of the frame 17 has formed thereon a pair of offsetareas 21 and 22 and one or more fingers or projections 23. Insulatedterminal jacks 24 and 26 are mounted by means of locking nuts 27 on theoffset areas 21 and 22, respectively, so that the terminals 29 and 28respectively project rearwardly of the frame 17. Extending betweencontacts 28 and 29 is a common contact element, which in the preferredembodiment is a helical spring 30. Helical spring 30 is normally undertension and has spaces 25 between adjacent convolutions of the spring.

One or more switch blade carriers 31 are slideably mounted onprojections 23 and held in place through cooperating detent elements tobe described later. Each switch blade carrier 31 pivotally supports aflat spring metal strip 30. The number of such carriers may vary ascircumstances dictate.

The parts of the switch thus far described are all metallic so thatthere is electrical continuity between the housing 10, frame 20, fingersor projections 23, all of the carriers 31 and the spring metal strips32. As noted earlier, spring contact element 30 is insulatingly mountedon the frame 17 and is under tension between contacts 28 and 29 of thejacks 26 and 24, respectively. Consequently an electrical circuit iscompleted when one of the switch blade elements 59 moves into contactwith the contact element 30.

Each switch blade carrier 31 comprises side plates 38 and 39 (see FIGS.5 and 8) joined together by a hollow channel 40. The distance betweenthe side plates 38 and 39 is slightly greater than the thickness of theswitch blade 32- to allow free movement thereof. Each side plate hasformed therein an aperture 41 and 42, respec tively, through whichpasses a pivot pin 43. Pivot pin 43 has a post 45 integral therewith andextending outwardly from side plate 39. Post 45 is slightly larger indiameter than pivot pin 43 and forms a shoulder (not shown) which abutsside plate 39. The end of the pivot pin extending through side plate 38is upset as at 46 forming a rivet holding the side plates 38 and 39 infixed position. Pivot pin 43 also passes through a hole '47 in the upperend of the spring metal strip 32 so that the strip may pivot about thispoint.

A switch biasing spring 48 is mounted on post 45. Short arm 51 of spring48 has a hook portion 52 which passes through apertures in side plates38 and 39. The long arm 53 of biasing spring 48'extends downwardlytherefrom and is hooked about spring strip 32 below pivot pin 43.

Spring tab 56 depending from channel 40 is impressed with a dimple 57which cooperates with a groove or indentation 58 on the inside surfaceof body portion 20 below below each projection 23. Dimple 57 forms withgrooves 58 cooperating detent devices which hold the carriers 31 on theprojections 23. In addition, these detent elements assure goodelectrical connection between the carriers and the frame.

The upper end 59 of spring strip 32 forms the switch blade element ofthe strip with the spring contact 30. This end may be silver plated tominimize corrosion. Contact 30 may be formed of a Phosphor bronze springwhich is highly resilient and has good electrical conductivity.

Referring to FIGS. 4, 6 and 7, when an article or object is moving alonga path denoted by the arrow X and strikes one or more of the springstrips the arm or arms 35 are pivoted about pivot pin 46 to move the tip59 into engagement with the contact 30. Inasmuch as the conbottom wall12, top wall 13 and side walls 14 and 15, volutions of the helicalspring 30 have a pitch slightly larger than the thickness of switchblade 32, the blade will normally pass between the convolutions to forma wiping contact with at least one of the convolutions. However, shouldthe blade be located so that the edge thereof strikes one ofthe turns ofthe convolutions on the outer periphery of the spring, the spring willmove longitudinally in one direction or the other depending upon whichside of that particular convolution the edge of the contact strikes sothat the contact will normally pass between the convolutions and makewiping contact with either one or adjacent or both adjacentconvolution's.

In order to present a broad surface for engagement of the spring stripby an object moving along the path X, spring strips 32 may be twistedintermediate its ends at 33 dividing the strip 32 into two sections, oneof the sections forming the switch blade contact elment 59 while theother section forms the actuating arm 35. This construction is shown inFIG. 5a.

The top side 13 of housing has integral therewith a projecting flange 61which overlies all of the contact elements so that falling debris willnot enter in and interfere with the operation of the switch. For similarreaons the upper edges of carrier side plates 39 and 40 are tapered asat 62 and 63 so that falling debris will slide therefrom.

While we have described and illustrated a preferred embodiment of ourinvention, we wish it to be understod that we do not intend to berestricted solely thereto but that we do intend to cover allmodifications thereof which would appear to one skilled in the art andwhich come within the spirit and scope of our invention.

We claim:

1. An electrical switch comprising a frame, a fixed resilient helicalspring contact element, means for mounting said helical spring contactelement on said frame in tension so as to have uniform spaces betweensuccessive convolutions thereof, a plurality of switch blade contactelements, means for independently mounting each of said switch bladecontact elements on said frame for independent pivotal movement relativethereto between a first position and a second position definingdifferent electrical conditions with respect to said helical springcontact element, spring means for biasing each of said switch bladecontact elements to one of said positions, each of said switch bladecontact elements having an arm integral therewith for moving said switchblade contact elements from said first position in opposition to saidbiasing spring means to said second position, and each of said switchblade contact elements having a thickness less than the spacing betweensuccessive convolutions of said helical spring contact element so thateach of said switch blade contact elements make a wiping contacttherewith.

2. An electrical switch comprising a frame, a carrier, a contact blade,means pivotally mounting said contact blade on said carrier, springmeans on said carrier biasing said contact blade to one position on saidcarrier, 'means for mounting said carrier on said frame, a helicalspring contact element forming with the contact blade an electricalswitch, means insulatingly mounting said helical spring on said frame,and means for moving said contact blade against the action of saidbiasing spring means to change the electrical relationship of saidcontact blade and said helical spring contact element.

3. An electrical switch as defined in claim 2 further includingcooperable detent elements on said frame and on said carrier forreleasably securing said carrier on said frame.

4. An electrical switch as defined in claim 2 wherein said contact bladehas a thickness which is less than the spacing between successiveconvolutions of said helical spring whereby said blade makes wipingcontact with a convolution of said helical spring.

5. An electrical switch comprising a frame member, a carrier member, aswitch blade contact element, means pivotally mounting said switch bladecontact element on the carrier member, means for mounting said carriermember on said frame member comprising a finger on one of the members,and a channel on the other of said members slideably fitted over saidfinger, a helical spring forming with said switch blade contact elementan electrical switch and means insulatingly mounting said helical springbetween spaced points on said frame member.

6. An electrical switch as defined in claim 5 including cooperatingdetent elements on said carrier member and said frame member forreleasably securing the carrier member on said frame member.

7. An electrical switch as defined in claim 5 further including a springtab on one of said members engageable with the other of said members tofrictionally hold said members in assembled relation.

8. An electrical switch as defined in claim 7 including a detent elementformed on said spring tab onsaid one member, a complementary detentelement formed on the other of said members, said detent elements beingeifective to frictionally secure said carrier member on said framemember.

9. An electrical switch comprising a frame member, a carrier member, afirst contact element, means pivotally mounting said contact element onsaid carrier member, mounting means for mounting said carrier member onsaid frame member, said mounting means comprising a finger on one of themembers and a channel on the other of said members slidably fitted oversaid finger, and a second contact element, means insulatingly mountingsaid second contact element on said frame member opposite a portion ofsaid first contact element whereby pivotable movement of said firstcontact element about said means pivotally mounting same on said carriermember moves said first contact element into electrical contact withsaid second contact element.

10. An electrical switch as defined in claim 9 wherein there are aplurality of said mounting means on said frame member and a plurality ofsaid carrier members, each carrier member and its associated contactelements forming electrical switches with said contact element on saidframe member.

References Cited by the Examiner UNITED STATES PATENTS 1,357,750 11/20Viets 200166 3,023,283 2/62 Wintriss 200-6l.4l

BERNARD A. GILHEANY, Primary Examiner.

9. AN ELECTRICAL SWITCH COMPRISING A FRAME MEMBER, A CARRIER MEMBER, AFIRST CONTACT ELEMENT, MEANS PIVOTALLY MOUNTING SAID CONTACT ELEMENT ONSAID CARRIER MEMBER, MOUNTING MEANS FOR MOUNTING SAID CARRIER MEMBER ONSAID FRAME MEMBER, SAID MOUNTING MEANS COMPRISING A FINGER ON ONE OF THEMEMBERS AND A CHANNEL ON THE OTHER OF SAID MEMBERS SLIDABLY FITTED OVERSAID FINGER, AND A SECOND CONTACT ELEMENT, MEANS INSULATINGLY MOUNTINGSAID SECOND CONTACT ELEMENT ON SAID FRAME MEMBER OPPOSITE A PORTION OFSAID FIRST CONTACT ELEMENT WHEREBY PIVOTABLE MOVEMENT OF SAID FIRSTCONTACT ELEMENT ABOUT SAID MEANS PIVOTALLY MOUNTING SAME ON SAID CARRIERMEMBER MOVES SAID FIRST CONTACT ELEMENT INTO ELECTRICAL CONTACT WITHSAID SECOND CONTACT ELEMENT.